Express through YouAndEye

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations only say the operation is not read-only, not idempotent, and not destructive; the description adds that the expression is temporary and that the firmware owns animation, which explains the device-driven temporal behavior. The sequence/message interaction is a useful behavioral disclosure beyond the schema. It does not describe possible side effects or return behavior, but the annotations provide no contradictions and the output schema covers return shape.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, front-loaded with the core purpose, no filler; the conditional note earns its place because it prevents a common invocation error. This is an ideal size for this tool.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Despite output schema and annotations, the definition is not complete enough for an agent to correctly use a complex 11-parameter tool. The most important required field (affect) and several behavior-shaping parameters are unexplained, and there is no mention of when temporary expressions expire or how firmware-sequenced expressions interact with other calls. The sequence/message note helps but is the only operational guidance.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

With 0% schema description coverage and 11 parameters, the description must carry the burden and largely fails to. It only explains the message/sequence relationship; the required affect parameter and key controls such as priority, gaze, intensity, ttl_ms, autonomy, text_mode, and behavior_mode are left undefined.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The phrase 'Show one temporary semantic expression on the local face' names a specific verb, resource, and scope, and 'temporary' distinguishes it from persistent state changes. It does not explicitly contrast with sibling tools like neutral or face_status, so it misses the top bar for sibling differentiation.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives direct conditional guidance: when sequence is set, omit message so the device can perform its coordinated eye/OLED beat. It conveys this is the tool for showing a temporary expression, but it never mentions when to prefer neutral, face_status, or face_capabilities instead, so exclusions are absent.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.